[FIX] mrp: avoid double write on production orders

Small improvement in order to not trigger twice the write
function on state

close #34884

closes odoo/odoo#38177

X-original-commit: d45d50b4f145a0bfb60465f7eb783a3c5fd85e6c
Signed-off-by: Arnold Moyaux <amoyaux@users.noreply.github.com>

addons/mrp/models/mrp_production.py

@@ -935,8 +935,7 @@ class MrpProduction(models.Model):
             'state': 'done',
             'product_uom_qty': 0.0,
         })
-        self.write({'date_finished': fields.Datetime.now()})
-        return True
+        return self.write({'date_finished': fields.Datetime.now()})
 
     def do_unreserve(self):
         for production in self: